The compiler can take advantage of the allocation/deallocation
function's properties. We knew how to do this for Itanium but had no
support for MSVC-style functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254656 91177308-0d34-0410-b5e6-96231b3b80d8
Having to import an alias as declaration is not thinlto specific.
The test difference are because when we already have a decl and we are
not importing it, we just leave the decl alone.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254556 91177308-0d34-0410-b5e6-96231b3b80d8
The current code does not take alloca array size into account and,
as a result, considers any access past the first array element to be
unsafe.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254350 91177308-0d34-0410-b5e6-96231b3b80d8
This one is enabled only under -ffast-math. There are cases where the
difference between the value computed and the correct value is huge
even for ffast-math, e.g. as Steven pointed out:
x = -1, y = -4
log(pow(-1), 4) = 0
4*log(-1) = NaN
I checked what GCC does and apparently they do the same optimization
(which result in the dramatic difference). Future work might try to
make this (slightly) less worse.
Differential Revision: http://reviews.llvm.org/D14400
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254263 91177308-0d34-0410-b5e6-96231b3b80d8
This adds two thresholds to the sample profiler to affect inlining
decisions: the concept of global hotness and coldness.
Functions that have accumulated more than a certain fraction of samples at
runtime, are annotated with the InlineHint attribute. Conversely,
functions that accumulate less than a certain fraction of samples, are
annotated with the Cold attribute.
This is very similar to the hints emitted by Clang when using
instrumentation profiles.
Notice that this is a very blunt instrument. A function may have
globally collected a significant fraction of samples, but that does not
necessarily mean that every callsite for that function is hot.
Ideally, we would annotate each callsite with the samples collected at
that callsite. This way, the inliner can incorporate all these weights
into its cost model.
Once the inliner offers this functionality, we can change the hints
emitted here to a more precise per-callsite annotation. For now, this is
providing some measure of speedups with our internal benchmarks. I've
observed speedups of up to 23% (though the geo mean is about 3%). I expect
these numbers to improve as the inliner gets better annotations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254212 91177308-0d34-0410-b5e6-96231b3b80d8
The order in which instructions are truncated in truncateToMinimalBitwidths
effects code generation. Switch to a map with a determinisic order, since the
iteration order over a DenseMap is not defined.
This code is not hot, so the difference in container performance isn't
interesting.
Many thanks to David Blaikie for making me aware of MapVector!
Fixes PR25490.
Differential Revision: http://reviews.llvm.org/D14981
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They are as much trouble as aliases to declarations. They are requiring
the code generator to define a symbol with the same value as another
symbol, but the second symbol is undefined.
If representing this is important for some optimization, we could add
support for available_externally aliases. They would be *required* to
point to a declaration (or available_externally definition).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254170 91177308-0d34-0410-b5e6-96231b3b80d8
Add a simple initial heuristic to control importing based on the number
of instructions recorded in the function's summary. Add option to
control the limit, and test using option.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254036 91177308-0d34-0410-b5e6-96231b3b80d8
When the original binary is executed and sampled, the resulting profile
contains information on the original inline stack. We currently follow
the original inline plan if we notice that the inlined callsite has more
than 0 samples to it.
A better way is to determine whether the callsite is actually worth
inlining. If the callsite accumulates a small fraction of the samples
spent in the parent function, then we don't want to bother inlining it
(as it means that the callsite is actually cold).
This patch introduces a threshold expressed in percentage of samples
in relation to the parent function. If the callsite uses less than N%
of the total samples used by its parent, the original inline decision is
not re-applied.
I've set the threshold to the very arbitrary value of 5%. I'm yet to do
any actual experiments to see what's a good value. I wanted to separate
the basic mechanism from the tuning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254034 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements a minimum spanning tree (MST) based instrumentation for
PGO. The use of MST guarantees minimum number of CFG edges getting
instrumented. An addition optimization is to instrument the less executed
edges to further reduce the instrumentation overhead. The patch contains both the
instrumentation and the use of the profile to set the branch weights.
Differential Revision: http://reviews.llvm.org/D12781
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254021 91177308-0d34-0410-b5e6-96231b3b80d8
Analyze imported function bodies and add any new external calls to
the worklist for importing. Currently no controls on the importing
so this will end up importing everything possible in the call tree
below the importing module. Basic profitability checks coming next.
Update test to check for iteratively inlined functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254011 91177308-0d34-0410-b5e6-96231b3b80d8
The new function import pass exposed an issue when we import references
to local values on multiple importing passes. They are renamed on each
import pass, and we need to ensure that the already promoted and renamed
references existing in the dest module are correctly identified and
updated so that they aren't spuriously renamed again (due to a perceived
conflict with the newly linked reference).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254009 91177308-0d34-0410-b5e6-96231b3b80d8
Skip imports for weak_any aliases as well. Fix the test to check
non-import of weak aliases and functions, and import of normal alias.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253991 91177308-0d34-0410-b5e6-96231b3b80d8
The existing coverage tracker counts the number of records that were used
from the input profile. An alternative view of coverage is to check how
many available samples were applied.
This way, if the profile contains several records with few samples, it
doesn't really matter much that they were not applied. The more
interesting records to apply are the ones that contribute many samples.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253912 91177308-0d34-0410-b5e6-96231b3b80d8
We had two code paths. One would create names like "foo.1" and the other
names like "foo1".
For globals it is important to use "foo.1" to help C++ name demangling.
For locals there is no strong reason to go one way or the other so I
kept the most common mangling (foo1).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253804 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Add and instructions immediately after loads that only have their low
bits used, assuming that the (and (load x) c) will be matched as a
extload and the ands/truncs fed by the extload will be removed by isel.
Reviewers: mcrosier, qcolombet, ab
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14584
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253722 91177308-0d34-0410-b5e6-96231b3b80d8
If a function was originally inlined but not actually hot at runtime,
its samples will not be counted inside the parent function. This throws
off the coverage calculation because it expects to find more used
records than it should.
Fixed by ignoring functions that will not be inlined into the parent.
Currently, this is inlined functions with 0 samples. In subsequent
patches, I'll change this to mean "cold" functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253716 91177308-0d34-0410-b5e6-96231b3b80d8
While debugging some sampling coverage problems, I found this useful:
When applying samples from a profile, it helps to also know what line
offset and discriminator the sample belongs to. This makes it easy to
correlate against the input profile.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253670 91177308-0d34-0410-b5e6-96231b3b80d8
Terrifyingly, one of them is a mishandling of floating point vectors
in Constant::isZero(). How exactly this issue survived this long
is beyond me.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253655 91177308-0d34-0410-b5e6-96231b3b80d8
The nuw constraint will not be satisfied unless <expr> == 0.
This bug has been around since r102234 (in 2010!), but was uncovered by
r251052, which introduced more aggressive optimization of nuw scev expressions.
Differential Revision: http://reviews.llvm.org/D14850
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Summary: The new algorithm is more efficient (O(n), n is number of basic blocks). And it is guaranteed to cover all cases of multiple BB mapped to same line.
Reviewers: dblaikie, davidxl, dnovillo
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14738
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We currently bail out of global localization if the global has non-instruction users. However, often these can be simple bitcasts or constant-GEPs, which we can easily turn into instructions before localizing. Be a bit more aggressive.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253584 91177308-0d34-0410-b5e6-96231b3b80d8
This provides a way to force a function to have certain attributes from the command line. This can be useful when debugging or doing workload exploration, where manually editing IR is tedious or not possible (due to build systems etc).
The syntax is -force-attribute=function_name:attribute_name
All function attributes are parsed except alignstack as it requires an argument.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253550 91177308-0d34-0410-b5e6-96231b3b80d8
The masked intrinsics support all integer and floating point data types. I added the pointer type to this list.
Added tests for CodeGen and for Loop Vectorizer.
Updated the Language Reference.
Differential Revision: http://reviews.llvm.org/D14150
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253544 91177308-0d34-0410-b5e6-96231b3b80d8
